Over the past decade a great deal of information has been published about intrinsically conducting polymers, more commonly known as "synthetic metals". The basic interest comes from the fact that these new materials combine the physical and chemical attributes of plastics with the electrical, electronic, magnetic, and optical properties of metals or semiconductors.
Poly (vinyl chloride) (PVC) is extraordinarily useful as a commercial material. Among the thermoplastics, it ranks second only to polyolefins in total worldwide production volume. Remarkably, it has achieved this status despite its molecular instability toward heat, an instability that is much more pronounced than those of all its major competitors. In a technological sense, this difficulty has been overcome to a large degree, for otherwise the usage of PVC would never have reached its current level Commercial interest in PVC was first revealed in a number of patents independently filed in 1928 by Carbide and Carbon Chemical Corporation, Dupont and IG Farben.
From the present research studies, it is summarized that the characteristics of poly vinyl chloride [PVC] changes according to the dosage of electron beam irradiation. That is amorphous nature of PVC changes to crystalline and conjugate double bond and free radicals are formed due to the degradation. The free radicals formed due to scission process in responsible at higher energy radiation. The electrical conductivity of polyvinyl chloride after irradiation slightly increases with electron beam radiation dose. It is due to increase in crystallinity in the polyvinyl chloride after electron beam irradiation and production of free radicals due to scission or crosslinking in PVC.
Table of Contents
1. INTRODUCTION
1.1 Introduction to polymers
1.2 Orientations of the work
1.3 Scope
2. RADIATION EFFECTS ON POLYMERS
2.1 Introduction
2.2 Radiation sources
2.3 Microtron
2.4 Terminology and units
2.5 Radiation induced chemical changes in polymer
3. EXPERIMENTAL METHODS
3.1 Preparation of sample
3.2 Thickness measurement
3.3 Irradiation
3.4 Electrode coating
3.5 X-ray Diffraction
3.6 Calculation of crystallinity
3.7 IR spectra
3.8 Measurements
4. RESULT AND DISCUSSION
4.1 X-ray Diffraction analysis
4.2 FTIR Analysis
4.3 Conductivity Measurements
5. CONCLUSION
Research Objectives and Themes
The primary objective of this work is to investigate the effects of high-energy electron beam irradiation on the electrical properties, specifically the resistivity, of polyvinyl chloride (PVC). The research seeks to determine how varying radiation doses influence the material's conductivity and structural characteristics by comparing I-V performance before and after irradiation.
- Irradiation effects on polymer molecular structure (chain scission and cross-linking)
- Characterization of PVC crystallinity using X-ray diffraction techniques
- Analysis of chemical bond alterations via FTIR spectroscopy
- Evaluation of electrical conduction mechanisms in irradiated PVC films
- Influence of electron beam parameters on material conductivity
Excerpt from the Book
1.1 Introduction to polymers
Polyvinyl chloride was accidentally discovered on at least two different occasions in the 19th century, first in 1835 by Henri Victor Regnault and in 1872 by Eugen Baumann. On both occasions, the polymer appeared as a white solid inside flasks of vinyl chloride that had been left exposed to sunlight. In the early 20th century, the Russian chemist Ivan Ostromislensky and Fritz Klatte of the German chemical company Griesheim-Elektron both attempted to use PVC (Polyvinyl Chloride) in commercial products, but difficulties in processing the rigid, sometimes brittle polymer blocked their efforts. In 1926, Waldo semon of B.F Goodrich developed a method to plasticize PVC by blending it with various additives. The result was a more flexible and more easily processed material that soon achieved widespread commercial use (13).
Summary of Chapters
1. INTRODUCTION: Provides an overview of polymers, specifically PVC, and details the scope and motivation behind studying radiation effects on these materials.
2. RADIATION EFFECTS ON POLYMERS: Discusses the fundamentals of radiation sources, how irradiation induces physical and chemical changes like cross-linking and degradation, and the role of environment and temperature.
3. EXPERIMENTAL METHODS: Describes the preparation of PVC samples, the irradiation process using a microtron, and the techniques used for characterization, including X-ray diffraction, FTIR spectroscopy, and resistivity measurements.
4. RESULT AND DISCUSSION: Analyzes the experimental data, showing how electron beam irradiation increases crystallinity and impacts electrical conductivity and chemical structure in PVC.
5. CONCLUSION: Summarizes findings that PVC characteristics change with irradiation, noting increased crystallinity and conductivity resulting from scission and cross-linking processes.
Keywords
Polyvinyl chloride, PVC, electron beam irradiation, polymer degradation, crystallinity, X-ray diffraction, FTIR analysis, electrical conductivity, resistivity, cross-linking, chain scission, polymer structure, radiation effects, material characterization, synthetic polymers.
Frequently Asked Questions
What is the core focus of this research?
The research fundamentally focuses on the impact of high-energy electron beam irradiation on the electrical resistivity and structural properties of polyvinyl chloride (PVC).
What are the primary scientific fields covered?
The work integrates polymer science, radiation physics, and materials engineering, specifically looking at electrical conduction in thin-film insulators.
What is the ultimate goal of the investigation?
The study aims to establish a clear understanding of how electron beam dosage correlates with changes in the PVC material's crystalline structure and its resulting electrical conductivity.
Which methodology is employed to analyze the polymer?
The study utilizes X-ray diffraction (XRD) for crystallinity assessment, FTIR spectroscopy for chemical analysis, and a Keithely source meter unit for I-V electrical characterization.
What does the main body of the work address?
The main body examines the physical and chemical alterations caused by high-energy electrons, providing a detailed analysis of how these changes manifest in both spectral data and electrical current-voltage (I-V) measurements.
What are the characterizing keywords of this work?
The most important keywords include polyvinyl chloride, electron beam irradiation, crystallinity, FTIR analysis, electrical conductivity, and polymer degradation.
How does the irradiation affect the crystallinity of PVC?
Experimental results indicate that the amorphous nature of PVC decreases as it becomes more crystalline upon irradiation, with no shift in peak positions, suggesting an alignment of polymer fragments.
Why is the study of PVC conductivity important?
Since PVC is widely used as an electrical insulator, understanding its performance when exposed to radiation—such as in space applications—is critical to preventing insulation failure and predicting component degradation.
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- A S Jagadisha (Autor), 2010, Effects of radiation on Polymer, Múnich, GRIN Verlag, https://www.grin.com/document/520275
